Phase transitions in SrTiO3-based solid solutions

Phase transitions in solid solutions of strontium titanate with titanates of the divalent metals Pb, Ba, and Ca are considered. It is shown that the critical concentration x(c) in the well-known expression relating the transition temperature to the polar state in SrTiO3 with the concentration x of divalent metals, T-c = A(x-x(c))(1/2), is practically the same for all impurities. For large values of x, the ferroelectric transition temperature T-c depends linearly on x. The volume and impurity contributions to the T,(x) relation are determined for this concentration range. (C) 1997 American Institute of Physics.